Composite roll for electrotinplating lines



y 1950 w. A. POWERS COMPOSITE ROLL FOR ELECTROTINPLATING LINES Filed May 13, 1946 INVENTOR.

W/l L /AM A. FDWEES lllllllll A I F IIIII'II l/ll/dr r iiiaiz.

A T7'OP/VEYS Patented July 4, 1950 COMPOSITE ROLL FOR ELECTRO- TINPLATING LINES William A. Powers, Niles, Ohio, assignor to Republic Steel Corporation, Cleveland, Ohio, a corporation of New Jersey Application May 13, 1946, Serial No. 669,249

8 Claims.

. troplated.

One important disadvantage attending this manner of electroplating was the arcing and burning and non-uniform flow of current which occurred under certain conditions. When a strip v of given width was being plated, metal was deposited on the conductive rolls along the edges of that strip. If thereafter a wider strip was to be plated the metal thus previously deposited on the rolls would interfere with proper contact of I the strip with the rolls and caused arcing, burning and non-uniform flow of current. As a result it was necessary either to provide a plurality of sets of rolls for metal of different widths or to clean deposited metal oil the rolls frequently and particularly when wider strip was to be plated on a given set of rolls. All these disadvantages have been avoided by the present invention.

Briefly stated, this invention contemplates continuous electroplating rolls having conductive surfaces which are disposed to engage the metal to be plated intermediate its side edges and nonconductive surfaces to engage the side edge pertions.

In the drawings accompanying and forming a part of this specification,

Figure 1 is a side elevational view, partly in section, of one form of roll embodying the present invention;

Figure 2 is a side elevational view, partly in section, of a pair of rolls one of which embodies a modified form of the present invention; and,

Figure 3 is a diagrammatic view showing part of a continuous electroplating system equipped with apparatus embodying the present invention.

The roll R of Fig. '1 comprises a metal body and electrically non-conductive sleeves in axially spaced position thereon. The metal body includes a central tube I and spindles 2 which extend into opposite ends of tube I and are secured in place as by weld metal 3. Spindles 2 are preferably hollow for part of their lengths beginning at their inner ends, as is indicated at 4. At their outer ends spindles 2 are necked down as at 5 01 mounting in bearings. Cylinders 8, composed of electrically conductive material, such as graphite. brass or copper have screw-threaded engagement with the spindles and servo, when slidablyen= gaged by conductors, to connect the rolls with a source of electrical current. Sleeves I surround and closely engage spindles 2 adjacent tb' centralf These sleeves have substantially the tube 5. same outside diameter as tube i so. that their outer surfaces are flush with the outer surface of tube I. sleeves and tube I is preferably greater than the width of any metal to be plated. The sleeves 7 consist of relatively poor electrically conductive material such as natural or synthetic rubber compositions or synthetic resins. tomeric material is used for it may be stretched over the spindles and will grip them tightly enough to prevent dislodgement and will deform when metal is pressed against it and thus permit good contact of the metal with the intervening metal part of the roll. Neoprene has given good results in actual use and may be considered as fairly representative of material suitable for sleeves I'.

In Fig. 2 roll R is quite like roll R of Fig. i,

substantially the only difference being that the metal part of roll R is made from one solid piece of metal, that is, the central strip engaging part I ii is solid and integral with solid spindle-like parts it. As is shown in Fig. 2, the strip is somewhat wider than the metal engaging portion It of roll R and each edge portion of the strip bears on the non-conductive sleeves i. The lower surface of strip I5 engages from edge to edge the non-conductive covering I6 of the roll I1. It will be understood from what has been said that when roll R of Fig. l is assembled with metal to be plated and a roll such as roll ii, the parts I and i will occupy the same general relationship and position with respect to that metal and roll I! as do parts I0 and I5 of Fig. 2.

While the sizes and relative proportions of the several parts of rolls embodying this invention may vary widely, satisfactory results have been obtained with rolls which were 48 inches long between the cuter ends of sleeves I, the central part I was 20 inches long and the metal being plated was 30 inches wide and overlapped each sleeve 1 to the extent of about 5 inches.

Fig. 3 depicts diagrammatically one manner in which the apparatus of Figs. 1 and 2 may be used in a. continuous electroplating system. Electrolyte is continuously supplied, as by a pipe 28, to each of several tanks 27. Anodes (not shown) are The over-all axial length of these Preferably, elas 3 disposed in tanks 2'! and are connected to a suitablesource of current( not shown). Pairs of rolls are arranged adjacent each end of the several tanks 21. The lower roll i! of each of these pairs may beconstructed as is shown in Fig. 2, while the upper roll of each of these pairs embodies the present invention and may be constructed according to either of Figs. 1 or 2. As has been noted. sleeves t of the upper rolls are connected to the above mentioned source of current (not shown). The metal to be plated is shown at I5 and is propelled by the several pairs of rolls with its lower surface in th electrolyte in the several tanks. The electric current flows thru the electrolyte, metal l5 and the upper rolls anddeposits metal on the under surface of metal as. The rolls grip the metal l5 with pressure sufficient to maintain the strip substantially horizontal, to make good electrical contact with the strip and to act as ringer rolls. Since the anodes extend transversely across the full width of metal 65 some distance below it and central parts i or it of the rolls have firm, substantially uniform, electrical contact over the central and major part of metal 55, the current density will be substantially uniform thruout the under surface of metal 95 and the plating metal will be deposited substantially equally and uniformly on metal it. Since sleeves 7 are poor electrical conductors, substantially no metal will be deposited thereon particularly along the side edges of metal l5, and the m loss will remain substantially constant and low during long periods of operation.

Having thus described my invention so that others skilled in the art may be able to understand and practice the same, I state that what I desire to secure by Letters Patent is defined in what is claimed. v

What i claimed is:

l. A roll for continuous electroplating apparatus comprising an electrically conductive roll body having a cylindrical portion to engage metal to be plated and carrying a sleeve of electrically poor conductive material adjacent to said portion, said sleeve and portion having substantially the same axes and outside diameters.

2. A roll for continuous plating apparatus comprising an electrically conductive roll body having a central cylindrical portion and sleeves of electrically poor conductive material on said body adjacent to said portion, said sleeves and body having substantially the same axes and outside diameters.

3. A. composite roll for continuous plating apparatus comprising an electrically conductive roll body having a central cylindrical portion and sleeves of elastomeric, electrically poor conductive material surrounding said body adjacent to opposite ends of said cylindrical portion, said sleeves having cylindrical surfaces axially aligned with and of substantially the same diameter as the cylindrical surface of said central portion,

4. A composite roll for continuous plating apparatus comprising an electrically conductive roll body having a central cylindrical portion and neoprene sleeves surrounding said body adjacent to opposite ends of said cylindrical portion, said sleeves and central portion having axially aligned outer cylindrical surfaces.

5. A composite roll for continuous plating apparatus comprising a metal body including a com tral tube and spindles extending into the ends of said tube and secured thereto, and elastomeric, electrically poor conductive sleeves on said spindles abutting the ends of said tube, the outer cylindrical surfaces of said tube and sleeves being axially aligned.

6. A composite roll comprising a metal spindle, having a central portion having a cylindrical surface, adjacent portions having cylindrical surfaces of reduced diameter, and elastomeric sleeves engaging and covering said adjacent portion and abutting said central portion and having out side surfaces flush with the surface of said central portion.

7. A composite roll comprising a metal spindle pair joined together by a metal cylinder and carrying sleeves of dielectric material, said sleeves engaging and covering said spindle pair and abutting said cylinder and having outside surfaces flush with the surface of said cylinder.

8. A composite roll for use in electroplating apparatus for the continuous electroplating of elongated relatively thin articles, such as steel sheet or strip stock, comprising an electrically conductive roll body having a cylindrical portion to engage an articl to be plated and carrying sleeves of electrically poor conductive material disposed'on opposite sides of the said cylindrical portion and abutting opposing edges of said cylindrical portion, said sleeves and cylindrical portion having substantially the same axes outside diameters, and said cylindrical portion having a width'less than the width of the article to be plated in the apparatus, whereby the edge portions of said article may bear upon the leeves, while the centralportion of the said article en gages said cylindrical portion of the roll.

WILLIAM A. POWERS.

REFERENCES QKTED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

